EFFECT OF HYPERLIPEMIA ON PULMONARY DIFFUSING-CAPACITY AT REST AND DURING EXERCISE

Since existing data suggest decreased pulmonary gas exchange at rest w hen hyperlipemic, the effect of alimentary hyperlipemia on steady-stat e pulmonary diffusing capacity for carbon monoxide (DLco) at rest and exercise was investigated. Twelve men were measured on two mornings af ter a 12-hr fast. One trial was performed with subjects in the fasting state, and the other three hours after ingestion of one gm fat per kg body weight. At each trial, venous blood was drawn at 0800 and again three hours later just before resting DLco measurement. The DLco was s ubsequently determined at a work intensity on the cycle ergometer of 4 9 watts, and then at an increased intensity sufficient to raise the he art rate to 150 bpm. Serum was examined spectrophotometrically to asse ss degree of lipemia as reflected by optical density. The DLco and ser um optical density data were anlayzed by ANOVA. Lipemia was significan tly increased three hours after fat ingestion (p < 0.05). Although mea n DLco, in ml/min/mmHg was lower following fat ingestion at both inten sities of exercise (49W = 37.1 fasted; 34.5 fed: 150 bpm = 49.8 fasted ; 44.6 fed), alimentary hyperlipemia did not significantly affect rest ing or exercise DLco.